Over recent years, the market for wireless communications has enjoyed tremendous growth. Wireless technology now reaches or is capable of reaching virtually every location on earth. This rapid growth in wireless communication technology and portable computing platforms has led to significant interest in the design and development of instantly deployable, wireless networks often referred to as “ad hoc networks” for both military and commercial applications.
In a wireless ad hoc network, mobile user nodes are linked within a limited geographical region, and all nodes participating in the ad hoc network operate cooperatively to forward data packets and determine whether the packets were successfully delivered from the original source to the final destination. A wireless ad hoc network has a number of advantages over cellular networks. For example, a wireless ad hoc network does not require infrastructure such as base stations or access points, and it does not require any centralized administration or control. As such, an ad hoc network can be entirely self-organizing between the mobile nodes that form the network. Thus, an ad hoc network can change position and shape in real time (i.e., dynamically) in order to adapt to a changing situational environment, such as a military operation, in times of emergency, such as earthquake, fire, or power interruption, and so forth.
In order to self-organize and operate cooperatively to forward information, all wireless nodes in an ad hoc network must continuously process and forward network information (e.g., data, voice, etc). In addition, all nodes in an ad hoc network must continuously send and receive routing overhead messages in order to maintain network connectivity. To support these operations, battery powered portable networking nodes in an ad hoc network continuously discharge their batteries. Consequently, users of such nodes are compelled to carry additional batteries and/or to use larger batteries to maintain connectivity to the ad hoc network for a given mission duration. Not only is it inconvenient to carry an additional quantity of batteries, it is highly undesirable in situations where mobility, weight reduction, and an individual's load carrying capacity are fundamental to mission success.
Thus, it would be desirable to have a power management scheme in a wireless ad hoc network that reduces power consumption at individual wireless nodes without sacrificing network responsiveness to changes in network traffic activity or network capability.